The Doctor Who Christmas special has been described as the "buddy movie you've always wanted".
An hour-long episode of the BBC One sci-fi drama is titled 'Last Christmas' and will see the titular Time Lord meet Santa Clause and showrunner Steven Moffat tells fans they should expect something "quite surprising".
He shared: "Well obviously as everyone knows from the end of 'Death in Heaven', it's the ultimate meeting of Christmas heroes; Santa Claus meets Doctor Who. The buddy movie you've always wanted.
"In addition to that, it's quite surprising - it won't be what some people expect because it's a thriller of an episode.
"The Christmas element is covered in the fairly notable form of Santa Claus and the elves and their sleigh. But the rest of it is very much 'Doctor Who' - scary, in a polar ice cap base, scientists under threat. I keep describing it as 'Miracle on 34th Street' meets 'Alien'."
Meanwhile Peter Capaldi says the much-hyped episode has a strong festive theme running through the storyline.
The latest Time Lord explained: "It's both really scary and really festive. It manages to be quite frightening and still have Santa Claus in it. It is extremely Christmassy but there is a plot line in it that is quite dark and I think Steven has done a brilliant job at balancing those two things.
"It's perfect for Christmas viewing - it supplies everything that 'Doctor Who' should supply at Christmas. It's scary but it leaves you feeling warm and cheerful."
Tagged in Steven Moffat Peter Capaldi